Poinsettia plant named Donner

ABSTRACT

A new and distinct cultivar of poinsettia plant named Donner, produced by grafting a seedling from the cross described to a plant of Super Rochford for the purpose of transferring the excellent branching characteristics of Super Rochford. Donner is characterized by its red, relatively large bracts, strong, vigorous growth habit, very early flowering, excellent branching, excellent foliage retention, resistance to heat delay of flower bud initiation when night temperatures are above 23° C., medium dark green leaves, and small cyathia cluster.

The present invention relates to a new and distinctive cultivar ofpoinsettia plant, botanically known as Euphorbia pulcherrima, andreferred to by the cultivar name Donner.

Donner was developed by me through controlled breeding by crossingMikkelsen Seedling No. 87-240-1 (seed parent) with Mikkelsen SeedlingNo. 86-131-1 (pollen parent). One of the seedlings from the cross wascharacterized by red bracts and poor branching. This seedling wasidentified by No. 88-457-1. This seedling was then grafted to theexcellent branching type cultivar Super Rochford (not patented) in anattempt to transfer the branching habit of Super Rochford to the redseedling. The graft was successful, resulting in the seedling having thebranching habit of Super Rochford and retaining all other desirablecharacteristics of the new seedling.

Asexual reproduction by stem cuttings in a greenhouse in Ashtabula, Ohiohas shown that the unique features of this new poinsettia are stabilizedand are reproduced true to type in successive propagations.

The following characteristics distinguish Donner from both its parentcultivars and other cultivated poinsettia of this type known and used inthe fluoriculture industry.

1. When 5 or more nodes are left after a pinch (apical tip removal)Donner will develop full length shoots from each node like SuperRochford, Yeletide (U.S. Plt. Pat. No. 7,316), and Feliz Navidad (plantpatent pending), while the original seedling 88-4571 will develop a fulllength shoot only from the upper 3 nodes, with the balance of shootsbeing greatly repressed.

2. Donner at 26 to 28 cm is shorter than the 88-457-1 seedling at 30 to32 cm when similar size plants are left after pinching, because there islittle or no apical dominance in the branched types. Thus, lower breaksmay grow longer than top breaks on a plant instead of the top 3 shootsbecoming dominant. Super Rochford is taller at 34 to 36 cm. Yuletide andFeliz Navidad are similar at 26 to 28 cm.

3. Donner has slightly lighter green leaves than the original seedling88-457-1, but the leaf color of Donner is similar to Super rochford andYuletide , with all of these cultivars being classified 147A in color(R.H.S. Colour Chart).

4. is more tolerant than 88-457-1 to low light levels and hightemperatures of the average home as leaves do not yellow and drop like88-457-1 under these conditions. When kept moist, Donner has excellentfoliage retention, similar to the comparison cultivars.

5. Bract coloration of Donner is 46B to 46C (R.H.S.), which is a lighterred than the 46B of seedling 88-457-1, with the bracts of Feliz Navidadbeing a still lighter red 45B to 45C.

6. Donner has a cyathia cluster (flowers in center of bract) that isslightly smaller in number and diameter (2-3 cm) than the originalseedling 88-457-1; much smaller than Yuletide, Super Rochford, andsimilar to Feliz Navidad.

7. Donner is resistant to heat delay of flower bud initiation when nighttemperatures are above 23° C., similar to 88-457-1 and Feliz Navidad,with Yuletide being slightly susceptible and Super Rochford verysusceptible to heat delay. This is of commercial importance, especiallyin the southern U.S.A. and warmer than normal autumns in the north.

8. Bract size of Donner is similar to Feliz Navidad at 30 to 32 cm,which is larger than Yuletide (26 to 28 cm) and Super Rochford at 20 to25 cm. Bracts are not as reflexed as Feliz Navidad but more reflexedthan Yuletide and Super Rochford. Cyathia will not split apart likeSuper Rochford but remain in a tight cluster like Yuletide and FelizNavidad.

9. All other characteristics of Donner are similar to the originalseedling, 88-457-1, such as early flowering under natural short days,similar shaped leaves and bracts, retention of cyathia under stressconditions and non-splitting cyathia.

The accompanying colored photographs illustrate the overall appearanceof Donner, and show the colors as true as is reasonably possible toobtain in colored reproductions of this type. The photograph on sheet 1is a front perspective view showing the foliage and bracts of a typicalplant of Donner. The photograph on sheet 2 is a top perspective view ofthe plant, showing the bracts more clearly. The photographs were takenon Nov. 26, 1991 in a rigid fiberglass greenhouse on an overcast day inAshtabula, Ohio.

The following detailed description of my new cultivar, based on plantsproduced in greenhouses in Ashtabula, Ohio during the Fall season of theyear. Plants were grown in 15 cm pots and measurements were takenseventeen (17) weeks after rooted cuttings were planted. Heightmeasurements were taken from the soil line of the container. The plantswere grown at 64°-68° F. night temperatures, under 3500-4000 footcandles of light, and with 250 ppm Nitrogen, 75 ppm Potassium, and 250ppm Phosphorous nutritional levels, with trace elements added. Habit ofgrowth, foliage coloration, leaf variegation, size of leaves and flowersize will be influenced by nutritional and environmental conditions,without, however, any variation in genotype.

Color references are made to The Royal Horticultural Society ColourChart except where general terms of ordinary dictionary significance areused.

Parentage: Controlled cross between female Mikkelsen Seedling No.87-240-1 and male Mikkelsen Seedling No. 86-131-1; resulting seedling(88-457-1) then grafted to a plant of Super Rochford.

Propagation:

A. Type cutting.--Stem 5 to 6 cm long.

B. Time to root.--14 days at 21° C. Summer; 18 days at 21° C. Winter.

C. Rooting habit.--Abundant, thick, fibrous roots.

Plant description:

A. Form.--Upright; when apical meristem is removed (pinching) leaving 5or more nodes above soil line to pot, generally all lateral shoots willemerge and develop.

B. Habit of growth.--Strong, thick stems with excellent branch anglesthat hold bracts up for good display of color. Bottom stems break firstand elongate faster than upper stems, resulting in the upright growthhabit with bract display on upper 2/3 of plant. Growth is vigorous andDonner can easily be grown with use of proper scheduling system withoutchemical growth regulators.

C. Foliage.--Leaves are alternate and borne on 5.0 to 6.0 cm longpetioles which have a reddish purple cast. The last 2-3 leaves beforetrue bract leaves also turn the same red color as bracts. 1. Size:Mature leaves are 12 to 14 cm long and 7 to 9 cm wide at broadest pointnear basal area of leaf. 2. Shape: More lanceolate than ovate withacuminate apex and rounded base. 3. Texture: Upper glabrous; lowerglabrous and rugose because of protruding veins. 4. Margin: Entire. 5.Color: Young foliage, top side, closest to but slightly darker than144A. under side, 146B. Mature foliage, top side, 147A. under side,147B.

Flowering description:

A. Flowering habits.--Earliest flowering cultivar that inventor hasdeveloped; Donner appears to have a longer critical daylength for flowerinitiation. Under controlled daylength, development time isapproximately 8 weeks and appears even earlier because last 2 or 3 trueleaves turn red before bract fully develops. The early flower initiationis of commercial significance.

B. Natural flowering season.--November 10 to 15 under Ohio conditions.Flowering time under 11 hours of daylength at 20° C. is 8 weeks. Donnerdoes not heat delay (failure to set flower bud under night temperatureabove 23° C.).

C. Cyathia description.--Few in number in tight cluster at center ofbract; are stress tolerant, remaining in the involucre for aconsiderable time under low fertility, low light, high temperatureconditions even after pollen shed. Severe drying may cause them to drop.

D. Cyathia borne.--Stay closely clustered without growing apart(splitting). Usually 2 to 3 cm in diameter. Flowering can be initiatedany time of the year by controlling the daylength to approximately 11hours total. Cyathia will continue to initiate until daylength isgreater than approximately 13 hours.

E. Quantity of Cyathia.--Quantity is highly dependent on culturalpractices and can vary from minimum of 2 to 3 to more than 10.

F. Bracts.--1. Shape: First true bracts are more lanceolate, with laterformed bracts more oblong. First bracts 11 to 12 cm long and 6 to 7 cmwide with a 2 to 3 cm petioles; later bracts are 7 to 8 cm long and 3.5to 4.0 cm wide with 10 cm petioles. 2. Color at maturity: Upper side 46Bto 46c, under side 45C; young bract is similar in color except greenishwhen very immature. 3. Number of bracts: 10 to 15 normal number butcould be fewer or more depending on growing conditions. Bract diametervaries with growing conditions; for example, if plants are pinched andgrowth regulators are used.

G. Reproductive organs.--1. Stamens: numerous. a. Anther shape: oblong,color reddish. b. Filament color: reddish. c. Pollen color: yellow. 2.Pistels: a. Stigma shape: forked, color reddish. b. Style color:reddish. c. Ovaries: Celled, 3 in number, 3 mm when stigma is receptive,green. 3. Nectar cups: Generally 2 nectar cups on each cyathia, withnone or 1 occurring rarely; nectar readily available on maturingcyathia.

Disease resistance: Bracts are very resistant to botrytis damage even onvery old bracts (30 days or longer from full expansion). Small cyathiaarea helps prevent botrytis after nectar cups start exuding honey-likesubstance.

OTHER IMPORTANT CHARACTERISTICS

A. Upright growth habit with strong stems and excellent branch angles tohold up large bracts make Donner excellent for faster and easiersleeving for shipping without branch breakage.

B. Earliest flowering poinsettia cultivar developed to date undernatural short days, thereby eliminating the need for black cloth forearly November sales.

C. The leaves and bracts of Donner are more lanceolate than the moreovate leaves and bracts of Yuletide and Feliz Navidad, thereby providingvariation in bract and leaf form.

D. With proper scheduling Donner can be grown without growth regulators,thereby eliminating both a crop expense and a potential environmentalhazard.

I claim:
 1. A new and distinct cultivar of poinsettia plant namedDonner, as illustrated and described.